I was looking around YouTube for a demonstration of muscle contractions for something that we’re studying in school and stumbled upon something interesting that we didn’t cover: The Golgi Tendon. Its job is to protect certain muscle tendons from an overexertion or greater force than can be tolerated by the muscle. If I’m living weights and I’m lifting way more than I can handle, I’d rather my body tell my arm to stop for me than to rip the tendon off of the bone — wouldn’t you? Well, that’s what it does. It sends signal to an inhibitory interneuron that shuts down the muscle to reduce the force. It’s called the GTO — Golgi Tendon Organ.

The first part of the video covers the monosynaptic stretch reflex. In school they taught us this differently from what the video demonstrates. We learned a 4-step process with certain steps that occur simultaneously. They sort of show a signal that’s delayed in its traveling — that’s more confusing for a demonstration of a reflex. But, after that, is the Golgi Tendon at about 1:44. Well worth seeing.